1. Action
Devise with principle, God, and others the right course of action. If we ask God for strength to act right, commit, and follow through, our lives will change. Any progress is welcome. Perfection is unlikely.
2. Thinking
... the stream of thoughts and wordless perceptions running through the mind in real time.
I have no agency over what I think of, but agency can be acquired over what I think about. Redirect, redirect, redirect. Think about something else, deliberately, with vigour, and if necessary out loud. Practise does make perfect.
3. Beliefs
I can't change how I feel about an idea, whether I feel it is true, but my acceptance or rejection of an idea does not make it more or less true. I can change my beliefs by selecting the belief I would like to adopt, for instance that God is good and powerful and can guide me further into a happy useful life, then applying that over and over to each situation (by affirming it as a truth) until my experience proves it's true. It's possible to recognise something as true and simultaneously recognise one's own resistance: 'I know I am going to be OK, because they tell me I will, but I can't see it. Isn't it interesting I'm wrong, yet can't see it!'.
The above accounts for a large chunk of the last three Steps. Practised as a set, directed and powered by God, this will bring about change.